1. Field of the Invention
The present invention relates to handcuffs which cannot be picked by a foreign object such as a steel wire other than an associated key, and more particularly to handcuffs which are adapted to guide a foreign object inserted into a passageway to a protrusion preventing the foreign object from reaching a ratchet portion of a movable arm, and which is adapted to quickly disable an arrested person by permitting the movable arm to be quickly released from its engaged position.
2. Description of the Prior Art
Various kinds of handcuffs have been proposed up to now. Such prior art handcuffs are designed to be locked by inserting several locking pins thereinto from the outside. Therefore, the prior art handcuffs are easily unlocked in such a way that the handcuffs are applied with sufficient force to pull the locking pins out of the handcuffs and thus to allow its movable arms and fixed arms to be disengaged. Furthermore, since the prior art handcuffs have movable arms pivotably connected to fixed arms by pivot pins, the movable arms are easily released from the fixed arms by breakage or separation of the pivot pins. In addition, the prior art handcuffs may be easily unlocked in such a way that a fine pin such as a hairpin is inserted into the handcuff to displace a movable arm.
To overcome these problems, various handcuffs are proposed as disclosed in Korean Utility Model Publication Nos. 1993-204, 1993-2996 and 1996-3984. In particular, handcuffs, which are adapted to more easily put handcuffs on a criminal and to prevent unlocking by a foreign metal object, have been proposed.
In the known handcuffs, a movable arm is maintained in the locked position in such a way that a ratchet portion of the movable arm is inserted into a base body of a fixed arm through a passageway defined in the fixed arm and teeth of the ratchet portion are engaged with teeth of a pawl piece. In this state, the teeth of the ratchet portion are engaged with the teeth of the elastically supported pawl piece.
Since the pawl piece is elastically supported, if a metal piece having a thickness of 0.1 to 0.2 mm is inserted between the teeth of the movable arm and the teeth of pawl piece, the teeth of the movable arm are moved along the foreign metal piece in a direction opposite to the insertion direction and thus released from the pawl piece. Hence, such conventional handcuffs cannot prevent unwanted unlocking by foreign metal object.
To overcome this problem, handcuffs have been proposed by the inventor, which are provided with a partition plate disposed between a pair of pawl pieces wherein the partition plate includes bilaterally bent inclined protrusions to prevent a foreign thin metal piece from being inserted thereinto. In addition to the above handcuffs, the handcuffs may be provided with means for guiding a foreign metal piece to a constraining portion.
In general, when a user carries handcuffs on him, movable arms are inserted into a base bodies and teeth of the movable arms are engaged with teeth of pawl pieces. When the user arrests a criminal with the handcuffs, the user strikes the movable arm against a wrist of the criminal. By this impact, the movable arm is rotated in its insertion direction and then inserted into a passageway of the fixed arm, so that teeth of the movable arm are engaged with teeth of the pawl piece. However, since the teeth of the movable arm must pass over the teeth of the pawl piece while being in contact with the teeth of the elastically supported pawl piece, a time period required to complete the passage of the movable arm through the fixed arm is relatively long. Therefore, a user cannot achieve a prompt arrest of a criminal.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art and the prior handcuffs proposed by the inventor, and an object of the present invention is to provide a handcuff which is adapted to guide a foreign metal piece inserted thereinto upwardly to a blocking portion, thereby preventing an unwanted insertion of a foreign metal object.
Another object of the present invention is to provide a handcuff which is adapted to be quickly put on a wrist of a criminal.
In order to accomplish the above object, the present invention provides a handcuff comprising: a movable arm formed into a xe2x80x9cCxe2x80x9d shape, which is provided at its free end with a ratchet portion formed with dual lines of teeth; a pair of fixed arms formed into a xe2x80x9cCxe2x80x9d shape, which are pivotably connected at free ends thereof to the other end of the movable arm by a pivot pin and are integrally provided at their other ends with rectangular base bodies; a partition plate interposed between the pair of base bodies of the fixed arms to define a passageway allowing the movable arm to pass therethrough, and having a central reception cut portion, and which is provided with a dividing protrusion and bilaterally bent protrusions at an inlet of the passageway; a pair of frame plates disposed between the pair of base bodies of the fixed arms and the partition plate, each of the frame plates having a reception cut portion, and which are provided with upwardly inclined surfaces and blocking protrusions at the inlet of the passageway such that a gap is defined between the bilaterally bent protrusions of the partition plate and the upwardly inclined surfaces, thereby guiding a foreign metal object inserted into the passageway to the blocking protrusions through the gap; a pair of pawl pieces biasedly supported in the reception cut portions of the pair of frame plates, and which are provided at their free ends with teeth to be engaged with the teeth of the movable arm; and a leaf spring received in the reception cut portions of the pair of frame plates to bias the pair of pawl pieces toward the ratchet portion of the movable arm.
Preferably, the most proximal teeth of the teeth are formed with slanting surfaces for causing the proximal teeth to have an obtuse angle at their apex, whereby when the movable arm is pulled out of the base bodies of the fixed arms, the innermost teeth of the teeth pass over the most proximal teeth of the movable arm, thereby maintaining engagement between the innermost teeth of the pawl pieces and the most proximal teeth of the movable arm.